Thirty, Flirty, and Thriving
by melswrites
Summary: When Clarke wishes to be a "grown-up" after a fight with her best friend, she wakes up to find herself seventeen years older. Bellarke 13 Going on 30 AU.


"You're such a nerd, Bellamy."

Bellamy scoffed, a hand over his heart in mock outrage. "There is _nothing_ nerdy about the Battle of Okinawa, Clarke! I know everyone prattles on about the atomic bombings of Hiroshima and Nagasaki, but the Battle of Okinawa was the spark that started the series of events that led to the Japanese surrender in World War II!" He cleared his throat, pulling his backpack higher up on his shoulder. "Besides, I'm not a _nerd_ , because people who are into history are called history _buffs_ , because of our strong, sensual arms. If anything, _you're_ the nerd, miss science geek."

Clarke elbowed him in the side, attempting to hide the growing grin on her face. "I'll remember that the next time you ask me to help you out with your chemistry homework, Blake."

Bellamy grabbed her hand and got down on one knee, looking up at her with pleading eyes. "Clarke Griffin, goddess of all things science, I beg you _please_ don't leave me hanging with the periodic table test looming in the very near distance."

Clarke barked out a laugh, then reached out to ruffle his already messy hair with her free hand. "Get up, you dork."

"Not until you promise you won't leave me."

Clarke smiled, giving his hand a small squeeze. "Fine. I _pinky swear_." She held her pinky out to him, eyebrows raised. Bellamy grinned back and locked his pinky around hers, shaking it for good measure.

"Now isn't this cute," a new voice said, belonging to none other than John Murphy.

Clarke rolled her eyes and Bellamy stood up, awkwardly rubbing the back of his neck with his hand. "Don't you have anything better to do, Murphy?" Clarke asked, crossing her arms over her chest.

"I was about to ask your friend here the same question. Still hanging out with the middle schoolers, Blake? Thought you'd be over robbing the cradle after Reyes basically propositioned herself to you."

Clarke looked over at Bellamy, eyebrows raised in question. Bellamy avoided her gaze, choosing to stare daggers at Murphy. "That's none of your business, Murphy."

Murphy smirked, walking closer to the two until he was right in Bellamy's face. "What's the matter, Blake? Can't handle girls your own age, so you have to take a dip in the kiddie poo-"

In the blink of an eye, Bellamy reached out and punched Murphy square in the nose, a sickening crunch sounding before the blood started pouring out. Snapping out of it quickly, Clarke grabbed onto Bellamy's arm and pulled him away, knowing a teacher would show up soon enough to check on the commotion, and the last thing Bellamy needed was another mark on his permanent record.

She pulled him up two flights of stairs and into the girl's bathroom, ignoring the squeals of the girls already inside as they rushed for the exit. Clarke threw her backpack to the floor and started digging through her backpack, producing an old rag from it. Bellamy raised an eyebrow at her. "Why do you carry a rag around with you?"

"Because you're too predictable, Blake. Now give me your hand."

Bellamy reluctantly held out his arm, and Clarke gingerly grabbed his hand and carefully examined it. She wet the rag and dabbed at it; luckily, none of the blood was Bellamy's. She felt his hand twitch under her grasp, but he made no other indication to show he was in pain; damn Blakes and their damn pride. "It's gonna bruise, you know."

"Yeah, Clarke, I'm well aware of what happens when I punch someone."

"Don't be an asshole. I'm just trying to help, Bellamy."

Bellamy sighed and pulled his hand away, flexing his fingers and wincing. "Sorry.. I'll be fine, okay? Don't you have class soon?"

"Mr. Kane can wait. He owes me after I didn't tell anybody about how a thirteen year old kicked his English teacher ass at Scrabble during the last Griffin family Game Night."

Bellamy laughed. "Seriously? And here I thought you were just a science whiz, Princess."

"I liked it better when you called me a 'goddess'." Bellamy laughed again, and Clarke felt herself smiling along with him. "Are you still coming over to study tonight? I have to put the finishing touches on my history diorama, and you have that periodic table test you mentioned.."

Bellamy nodded, cradling his bruising fist in his other hand. "I'll bring the Cheetos, you bring the flash cards?"

"You know me so well, Blake." She gave him a light punch on the arm, and he chuckled and threw an arm around her shoulders.

"Let's get me out of here before somebody sees me leaving the girl's bathroom. I don't think my reputation could take that big of a blow."

Clarke rolled her eyes and smirked. "Sometimes I forget how fragile the male psyche is."

The two exited the bathroom, arm in arm, and ran straight into Finn Collins and Raven Reyes. Clarke felt her breath catch in her throat, and Bellamy's arm tightened around Clarke as he saw the wolfish look on the younger boy's face. Finn smirked, his arm loosely dangling over Raven's shoulder. "You're Clarke, right? I think we were in the same math class last year."

Clarke tucked a strand of hair behind her ear. "Yeah, um… Hawkins sure was a riot, yeah?"

Finn snorted. "Yeah, let's go with that. Anyway, you're really good at science stuff, right?" Clarke nodded. "Well, Raven and I were talking, and I think it'd be really cool if you could help us out a little. She's got this big auto shop midterm and I'm starring in the school musical, of course," Bellamy rolled his eyes, though it went unnoticed by the other three people around him, "so we're a little strapped for time. But… if you maybe, you know, ran the experiments for us, developed a hypothesis, maybe keep track of everything and make a nice, neat poster charting the experiment… That would honestly be the coolest."

Clarke nodded and looked down at her feet. "Yeah, I-uh, I could probably do that."

"Wicked. Come on, I'll walk you to class and fill you in on the whole thing."

Clarke quickly untangled herself from Bellamy and made her way over to Finn, grinning at Bellamy over her shoulder as Finn placed a hand on the small of her back. Bellamy grimaced and turned to walk the other way, even though his class was in the same direction Clarke and Finn were heading. He was stopped by a hand on his arm, and when he turned he saw Raven with her arms crossed over her chest, eyebrow cocked. "Are you honestly into that kid over there?"

Bellamy sneered, pulling his arm away. "I think you should be asking your boyfriend that question."

"Please, Finn's just using her to get a good grade in science. He'd get kicked out of the musical otherwise."

Bellamy narrowed his eyes and crossed his arms over his chest. "Come again?"

"You really think Finn would be into _that_? Please, he'll throw her away like a used tissue once we've gotten an A on our science project." Bellamy clenched his fists and turned away from Raven, making a beeline for whatever empty room he came across first out of Raven's eyeline. "My offer still stands, you know!" Raven called after him, but Bellamy wasn't listening.

* * *

Clarke ran up to the door when she heard the loud knocking, taking a beat to smooth her frizzy hair down before opening it. Her smile fell when she saw it was Bellamy. "Oh, it's just you."

Bellamy quirked an eyebrow. "Yeah...just your best friend/study partner, who you confirmed study plans with just a few hours ago."

Clarke slapped her hand to her forehead. "Shoot, I knew I forgot to do something!" Bellamy raised the same eyebrow again. "Finn's coming over to pick up his project in a little bit."

Bellamy let out an exasperated groan. "Really, Clarke? You actually did the whole fucking project for him?"

"Yes, really, and watch your language." She looked around and lowered her voice. "My mom's around here somewhere."

"Oh, Abby's actually home for once?" Bellamy asked, not lowering his voice in the slightest. "Abby!" he yelled, pushing past an aggravated Clarke as he made his way into the kitchen.

"Bellamy Blake, what a surprise," Clarke heard her mom say dryly from the kitchen. Clarke let out a loud sigh and closed the front door, dragging her feet as she walked towards the kitchen. "What's the occasion?"

"Study date," Bellamy said, holding up his notebook and giant bag of Cheetos (the puffy kind, of course).

"Okay, it's not a _date_ ," Clarke said. Bellamy turned to look at her, a smirk on his face. Clarke cleared her throat and twirled a strand of hair around her finger. "Well, it's not!"

Bellamy turned back to Abby. "She's right; date was probably the wrong word to use. We're just studying, two platonic kids and some notecards and Cheetos."

Abby didn't look convinced, but she nodded slowly. Well, you know the rules: basement door stays open, no loud music, no illegal activities."

"Got it, Mom," Clarke said, grabbing Bellamy by the arm and dragging him out as quickly as he would let her.

"Nice seeing you again, Abby!"

"It's been a pleasure as usual, Bellamy."

Clarke's grip tightened around Bellamy's arm-her nails were probably digging in a little bit, judging by the "ow" that slipped past Bellamy's lips. She dragged him until they were safely down the flight of stairs that lead to the basement, before turning and smacking him across the side of his head. "You're such an idiot."

"Hey, wow, violence! You're always telling _me_ that violence isn't the answer, yet here we are!"

"God, shut _up_ , Bellamy!"

"Why don't you _make me_ , Princess!"

Clarke went to retort, when she realized how close they'd gotten. Her eyes flicked up to his, and she felt some of her anger melt away. The look in his eyes told her the same had happened to him, but neither of them made a move one way or the other. Finally, Clarke broke their staring contest and walked across the room, rolling her shoulders back in an attempt to ease some of the tension. "So I think my diorama is basically done… I just- I don't know," she ran a hand through her hair, "it still needs _something_."

"I think I've got an idea," Bellamy said, an indiscernible look on his face as he reached into his backpack. He shook it off quickly, though, and his usual smirk found its way onto his face. "Now, you're not allowed to laugh, okay?"

"No promises."

Bellamy rolled his eyes and pulled out a little packet of something-Clarke squinted and read "Wishing Dust". She covered her mouth in an attempt to hide the growing grin on her face. Bellamy sighed. "I told you not to laugh."

"And I said 'no promises', remember?" The exasperated look on Bellamy's face caused her to double over, all but falling over to the floor with laughter. "Clarke, come on. It's not _that_ funny."

"Yes-it-is-," she said between gulps of air, clutching at her side.

Bellamy clenched his jaw and crossed his arms over his chest. "I'll wait."

Clarke's laughter slowly subsided, and she took a deep breath to calm herself completely. "Okay, what's with the wishing stuff?"

Bellamy ripped it open with his teeth and walked over to her diorama, sprinkling some over it. "Octavia poured a packet over one of my dioramas freshman year and I ended up getting an A, so it's kind of a superstitious thing now. I thought maybe you could use a little luck, too."

The mocking grin on Clarke's face softened, and she walked forward and wrapped her arms tightly around Bellamy's waist. He seemed to be in shock for a second, but eventually his arms wrapped around her, and Clarke rested her forehead against his shoulder. "Thanks, Bell."

"Anytime, Princess. Now, can we-"

The doorbell interrupted him, and Clarke's head shot up as she looked towards the basement door. "He's here," she said quietly. She pulled herself away from Bellamy and sprinted up the stairs, quickly yelling, "I'll be right back!" over her shoulder as she left Bellamy alone for the second time that day. Bellamy groaned and leaned against the table, starting a chain of events that nobody could have predicted.

When Clarke came back downstairs with Finn Collins, Bellamy was in a heap on the floor, Clarke's diorama was smashed, and there was puffy paint all over Finn's science project. Bellamy looked up at Clarke with wide eyes, pushing himself up off the floor. "Clarke, I can explain-"

Get _OUT!_ " she yelled with a force that Bellamy hadn't known she'd been capable of, and fucking Collins stood behind her with a stupid smirk on his face. Bellamy stared at her pleadingly for a moment, hoping she'd have a change of heart, but no such luck. He ran up the stairs without looking back, shoulders slumped and look of defeat on his face.

Clarke swallowed angry tears, her scowl fading as she turned to Finn. "I'm sorry, Finn… I can try to fix it, or maybe make a new one. I- I have all of the information written down somewh-"

"I'm just gonna bounce, if that's alright with you? I just stopped by on the way to musical practice. Catch ya on the flipside, Griffin."

Clarke watched Finn leave, her heart dropping into her stomach. She backed up until she hit the edge of the table her ruined diorama sat on and slid down to the floor, hitting the back of her head repeatedly against it and muttering, "I wish I was a grown-up…" over and over again. The wishing dust that had coated her diorama floated around her, falling into her hair and onto her eyelashes and clothes, and that was the last thing she remembered.


End file.
